Flat spring clamping assembly for chair back



Dec. 27, 1966 A. CIUFFINI ET AL FLAT SPRING CLAMPING ASSEMBLY FOR CHAIR BACK Filed May 20, 1965 H lu i' United States Patent 3,294,441 FLAT SPRING CLAMPING ASSEMBLY FUR CHAIR BACK Aurelio Ciuflini and Philip J. Williams, Bridgeport, (1011111.,

assignors to Stewart-Warner Corporation, Chicago,

11]., a corporation of Virginia Filed May 20, 1965, Ser. No. 457,408 6 Claims. (Cl. 297-496) This invention relates to an improved assembly for fastening a tiltable chair back to a chair iron.

In certain chairs, particularly secretarial type chairs, it is a general practice to provide a back which tilts or pivots relative to the seat. The seat is rigidly fastened to a chair iron and the back is mounted on the chair iron for tilting in a vertical plane only, and restrained from pivoting in a horizontal plane relative to the chair iron seat. The tilting or pivot structure may be interconnected between the back and the chair iron by multiple screws or rivets, necessitating considerable assembly work, or by specially formed brackets on the chair back and pivot structure interconnected by means of a single Wheel-like nut. Such arrangements may be expensive, and in addition often extend beyond the periphery of the chair seat and present an unsightly appearance.

It is, therefore, one object of the present invention to provide a facilely assembled, tiltable chair back on a chair iron.

It is another object of the present invention to provide a more economical and durable assembly for tiltably interconnecting a chair iron with a chair back.

It is still another object of the present invention to provide an improved camouflaged connection between a tiltable chair back and a chair iron.

Other objects and features of the present invention will become apparent on examination of the following specification and claims, together with the drawings, wherein:

FIG. 1 schematically illustrates a chair employing the principles of the present invention;

FIG. 2 is a top elevational view of a chair iron portion and the apparatus used in the present invention for tiltably interconnecting the chair back to the chair iron;

FIG. 3 is a sectional View of the apparatus shown in FIG. 2; and

FIG. 4 is a perspective view of the bracket used for interconnecting the back and chair iron.

A chair 14 is seen in FIG. 1. The chair 11 comprises a chair iron 12 carried on a post 14 and pivotally supported on pedestal 16. The chair iron it) carries a chair seat 18 and a chair back 20. The chair back 29 is supported on the chair iron it by a flat L-shaped spring member 22 having a lower horizontal leg 24 connected to the chair iron by a bracket assembly 26 located beneath the seat and within the bounds of the seat periphery where it is normally unseen.

The chair iron 12 comprises an elongate U-shaped member, as seen in FIGS. 1 and 2, carrying a pair of L- shaped seat support brackets 28. Each bracket 2% has a vertical leg fastened to a respective side leg 30 of the iron 12. The seat 13 is in turn fastened to the horizontal legs of the brackets 28. The forward portion of the iron 12 and brackets 28 are not shown since the shape thereof is basically similar to that shown for the rearward portion in FIGS. 1 and 2. The chair iron 12 has a back leg 32 in which a post support member 34 is fastened for receiving the post 14.

The clamping assembly 26 comprises a U-shaped clamping bracket 35 having side legs 38 spaced apart by approximately 2% and approximately 2 /4 long in overlapping engagement with the side legs 30 of the iron 12. An elongate slot 40, approximately .321 wide, is provided in each side leg 38, and a pin 42, extending through ZhZMAi-l Patented Dec. 2'7, 1966 ice appropriate holes approximately midway between the upper and lower edges of legs 3t), engages the slots 40. The pin 42 prevents inadvertent separation between the bracket 36 and iron 12, and the bracket 36 is movable approximately vertically with respect to the pin.

A bolt 44 extends through the back leg 32 of the chair iron 12, leg 24 of the L-shaped spring member 22, and back leg 46 of bracket 36, with the head of the bolt engaging a washer 48. An irregularly or square-shaped shank on the bolt 44 engages in a similarly shaped hole substantially .390" in the back leg 32 and about 1 /2" from the end of the channel 12 to prevent the bolt from rotating. If the spring leg 24 is simply provided with a hole, the bolt prevents longitudinal movement of the spring member 22 relative to the chair iron and bracket 36. The position of the hole in leg 24 is chosen to provide a desired spring resistance or firm back support. If the leg 24- is provided with either a series of holes or a slot, it may of course be adjusted relative to iron 12 for further selecting the desired spring resistance or back support. The pin 42 adds an additional restraining force to prevent relative movement between iron 12 and bracket 36.

The back leg 46 of bracket 35 is formed with a strengthening offset or rib portion 5%, which is joined to the side legs by arcuate portions 52 to provide appropriate strength and rigidity in the bracket. A wheel-like nut 54 is threaded on the end of bolt 4d to bring th offset portion 5i) of bracket 36 firmly against the bottom surface of leg 24 due to the large leverage available on the application of manual force to the nut. It will be noted that in this arrangement the bolt 4 is prevented from rotating by th channel 12 so that no tool is necessary to hold the bolt, and one or both hands are free to manipulate the nut. This is a desirable feature especially in view of the difficulty in inserting a tool past the spring to grasp the bolthead.

The opposite edges of leg 24 engage the opposite side legs 33 of bracket 36 so that the member 22 cannot rotate about the axis of bolt 44, as bracket 36 likewise is prevented from rotating by legs 36. The positioning of the spring member is, therefore, easily accomplished during assembly. The member 22 is thus firmly guided by the bracket 36 and held in proper position during assembly, and when clamped against the back leg 32 of the chair iron by nut 54, a large area of contact against the spring leg 24 is provided to aid in holding the spring firmly in position. The slots 40 permit the bracket 36 to occupy various vertical positions with respect to iron 12 to permit easy insertion of spring member 22 or for accommodating springs of varying thickness. The chair iron and back may thus be shipped in disassembled condition and easily assembled at a desired location with no special tools and with a minimum of effort.

The foregoing constitutes a description of one embodiment of the invention, the inventive concepts of which are believed set forth in the accompanying claims.

What is claimed is:

1. For use in connecting a flat spring member carrying a chair back to a U-shaped chair iron carrying a chair seat, the improvement comprising, a U-shaped bracket with the side legs of said bracket spaced for overlapping engagement with the side legs of said chair iron and opposite edges of said spring member, and a single bolt passing through the back leg of said iron, spring member and the back leg of said bracket for preventing longitudinal movement of said bracket, member and iron relative to each other and enabling said bracket to be clamped to said iron with said member held engaged against and between both said back legs, the side legs of said bracket spaced for engagement with the respective opposite edges of said spring member for restraining said member against rotation relative to the axis of said bolt.

2. For use in connecting a flat spring member carrying a chair back to a U-shaped chair iron carrying a chair seat, the improvement comprising a U-shaped bracket having a back leg for engagement with one surface of said spring member to hold the opposite surface of said member engaged against the back leg of said chair iron with the side legs of said bracket in overlapping engagement with the side legs of said U-shaped chair iron and the opposite edges of said surfaces, means for maintaining said bracket engaged on said iron and movable relative thereto along a single axis only for controlling the space between the back leg of said bracket and the back leg of said iron, a bolt in nonrotatable engagement with the back leg of said iron and having a threaded end portion passing through said member and the back leg of said bracket, and a nut for threaded engagement with the threaded end portion of said bolt to move said bracket relative said iron along said axis for clamping said fiat spring member between the back leg of said bracket and the back leg of said iron with the side legs of said bracket and iron cooperating to prevent rotation of said spring member in a plane perpendicular to said axis.

3. A combination comprising a flat spring member carrying a chair back, a U-shaped chair iron carrying a chair seat, a U-shaped bracket having a back leg for engaging said spring against the back leg of said iron, each side leg of said bracket in overlapping snug engagement with a respective side leg of said U-shaped member, and respective opposite edges of said spring member, a bolt in nonrotatable engagement with the back leg of said member and passing through said spring member and the back leg of said bracket to prevent longitudinal movement of said member, bracket and iron relative to each other, and a wheeled nut for threaded engagement in the end of said bolt to clamp said member between the back leg of said bracket and the back leg of said iron with said side legs co-operating to prevent rotation of said spring member in a plane parallel to said back legs.

4. For use in connecting a fiat L-shaped spring member carrying a chair back to a U-shaped chair iron carrying a chair seat, the improvement comprising a U-shaped bracket having a back leg for engagement with one surface of said spring member to hold the opposite surface of said spring member engaged against the back leg of said chair iron with the side legs of said bracket in overlapping engagement with the side legs of said U-shaped chair iron and the opposite edges of said surfaces, each side leg of said bracket having a slot therein, a pin passing through the side legs of said iron and said slots for maintaining said bracket engaged on said iron and movable relative to said iron for varying the space between the back leg of said bracket and the back leg of said iron, a bolt in nonrotatable engagement with the back leg of said iron and having a threaded end portion passing through said member and through the back leg of said bracket, and a nut for threaded engagement with the threaded end portion of said bolt to move said bracket relative said iron for clamping said flat spring member between the back leg of said bracket and the back leg of said iron with the side legs of said bracket and iron co-operating to prevent rotation of said spring member in a plane parallel to said back legs.

5. A combination comprising a fiat L-shaped member carrying a chair back, a U-shaped chair iron carrying a chair seat, a U-shaped bracket having an offset portion in the back leg thereof for engagement with one surface of said spring member to hold the opposite surface of said spring member engaged against the back leg of said chair iron with the side legs of said bracket in overlapping engagement with the side legs of said U-shaped chair iron and in overlapping engagement with opposite edges of said spring member surfaces, said bracket terminating at a position spaced within the projected peripheral boundary of said seat, means maintaining said bracket engaged on said iron and movable relative to said iron for varying only the space between the back leg of said bracket and the back leg of said iron, a bolt extending through said spring member and having an irregularly shaped shank portion for nonrotatable engagement with the back leg of said iron and a threaded end portion passing through the back leg of said bracket, and a nut for threaded engagement with the threaded end portion of said bolt to move said bracket relative said iron for clamping said flat spring member between said offset portion and the back leg of said iron with the side legs of said bracket and iron cooperating to prevent rotation of said spring member about the axis of said bolt.

6. For use in connecting a flat L-shaped spring member carrying a chair back to a U-shaped chair iron carrying a chair seat, the improvement comprising a U-shaped bracket having an offset portion in the back leg thereof for engagement with one surface of said spring member for holding the opposite surface of said spring member engaged against the back leg of said chair iron with the side legs of said bracket in overlapping engagement with the side legs of said U-shaped chair iron and in overlapping engagement with opposite edges of said spring member surfaces, said bracket terminating at a position spaced within the projected peripheral boundary of said seat, each side leg of said bracket having a slot therein, means passing through the side legs of said chair iron and said slots for maintaining said bracket engaged with said iron and permitting movement of said bracket side legs parallel to said chair iron side legs for varying the space between the back leg of said bracket and the back leg of said iron, a bolt passing through said spring member and having an irregularly shaped shank portion for nonrotatable engagement with the back leg of said iron and a threaded end portion extending through the back leg of said bracket, and a nut for threaded engagement with the threaded end portion of said bolt to move said bracket side legs relative said chair iron side legs for clamping said flat spring member between said offset portion and the back leg of said iron with the side legs of said bracket and iron co-operating to prevent rotation of said spring member about the axis of said bolt.

References Cited by the Examiner UNITED STATES PATENTS 899,504 9/1908 Bolens 297298 1,361,178 12/1920 Pipp 297298 2,364,261 12/1944 Wood 297-298 2,662,586 12/1953 Cramer 297304 X 2,692,012 10/ 1954 Cramer 297298 3,224,807 12/1965 Welch et al. 297807 FRANK B. SHERRY, Primary Examiner. G. Q. EINCH, Assistant Examiner. 

1. FOR USE IN CONNECTING A FLAT SPRING MEMBER CARRYING A CHAIR BACK TO A U-SHAPED CHAIR IRON CARRYING A CHAIR SEAT, THE IMPROVEMENT COMPRISING, A U-SHAPED BRACKET WITH THE SIDE LEGS OF SAID BRACKET SPACED FOR OVERLAPPING ENGAGEMENT WITH THE SIDE LEGS OF SAID CHAIR IRON AND OPPOSITE EDGES OF SAID SPRING MEMBER, AND A SINGLE BOLT PASSING THROUGH THE BACK LEG OF SAID IRON, SPRING MEMBER AND THE BACK LEG OF SAID BRACKET FOR PREVENTING LONGITUDINAL MOVEMENT OF SAID BRACKET, MEMBER AND IRON RELATIVE TO EACH OTHER AND ENABLING SAID BRACKET TO BE CLAMPED TO SAID IRON WITH SAID MEMBER HELD ENGAGED AGAINST AND BETWEEN BOTH SAID BACK LEGS, THE SIDE LEGS OF SAID BRACKET SPACED FOR ENGAGEMENT WITH THE RESPECTIVE OPPOSITE EDGES OF SAID SPRING MEMBER FOR RESTRAINING SAID MEMBER AGAINST ROTATION RELATIVE TO THE AXIS OF SAID BOLT. 